It is often desirable to couple a compound to another compound or material for a variety of applications including labeling and/or functionalizing a target compound or material. Such coupling processes can be used to couple small molecules and/or macromolecules together. For example, a carbodiimide coupling scheme, such as a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysulfosuccinimide (sulfo-NHS), can be used to couple two unique macromolecules including a carboxyl group or an amine group respectively.
Isatoic anhydride (also known as 2H-3,1-Benzoxazine-2,4(H)-dione) and derivatives thereof are generally used as intermediates in organic synthesis. However, they have also been used in coupling reactions and to modify materials. For example, WO2012076794A1 and U.S. Patent Application Publication 20130253179 disclose coupling isatoic anhydride or a derivative thereof to functionalize ribonucleic acid (RNA) on certain ribose portions of RNA. WO2007145940 discloses analyzing the structure of RNA molecules by labeling the molecules with N-methylisatoic anhydride. U.S. Pat. Nos. 3,346,327 and 2,150,968 disclose using isatoic anhydride and derivatives thereof for modifying wool and cellulose.
However, some coupling schemes require the use of expensive reagents and/or result in the formation of undesired side products which must be removed from the desired reaction product. In addition, some coupling reactions can be slow and/or are difficult to monitor and quantify in real time. Further, many of the coupling schemes including isatoic anhydride and derivatives thereof use non-aqueous reaction media which are generally less desirable.
Accordingly, a continuing need exists for compounds that can be used to label and/or functionalize a target compound or material and/or to couple compounds or materials together.